title: Susceptibility of BALB/c-nu/nu mice and BALB/c mice to equine herpesvirus 9 infection.
abstract: This study aimed to clarify the timing and infectivity of equine herpesvirus 9 (EHV-9) infection in BALB/c-nu/nu mice and their immunocompetent counterpart (BALB/c). Following intranasal inoculation with 10(5) PFU of EHV-9, specimens from 8 mice per group were collected at different times postinoculation (PI) and assessed using histopathology, immunohistochemistry for viral antigen, and quantitative real-time polymerase chain reaction for ORF30 gene expression. In BALB/c-nu/nu mice, EHV-9 antigen was abundant in olfactory epithelia of all inoculated animals, and in the olfactory bulb of 1 animal. In contrast, only 1 BALB/c mouse per time point had rhinitis, with mild to moderate immunopositivity starting from 12 to 48 h PI, followed by a gradual virus clearance at 72 h PI. Statistically, significant differences were noted in the immunohistochemistry reactions between the 2 mouse strains, indicating that BALB/c-nu/nu is more susceptible to infection. Relative expression levels of ORF30 gene in olfactory epithelia were significantly different between the 2 groups, with the exception of 12 h PI, when BALB/c-nu/nu animals showed dramatic increases in ORF30 gene expression level until 48 h PI, followed by a decline in expression level until the end of experiment. In contrast, the expression level in brains showed no differences between mouse strain except at 96 h PI. In both strains, the highest messenger RNA expression was detected at 48 h PI, followed by a decline in BALB/c mice, proving a rapid clearance of virus in BALB/c and a gradual slowing down of the increased expression levels in BALB/c-nu/nu.
authors.affiliation: Department of Veterinary Pathology and Microbiology, Faculty of Applied Biological Science, Gifu University, 1-1 Yanagido, Gifu 501-1193 Japan. Email: yanai@gifu-u.ac.jp.
authors.forename: E
authors.initials: E
authors.lastname: El-Nahass
authors.forename: K M
authors.initials: KM
authors.lastname: El-Dakhly
authors.forename: N
authors.initials: N
authors.lastname: El-Habashi
authors.forename: S I
authors.initials: SI
authors.lastname: Anwar
authors.forename: H
authors.initials: H
authors.lastname: Sakai
authors.forename: A
authors.initials: A
authors.lastname: Hirata
authors.forename: A
authors.initials: A
authors.lastname: Okada
authors.forename: R
authors.initials: R
authors.lastname: Abo-Sakaya
authors.forename: H
authors.initials: H
authors.lastname: Fukushi
authors.forename: T
authors.initials: T
authors.lastname: Yanai
mesh_terms: D000281:Administration, Intranasal; D000818:Animals; D000956:Antigens, Viral / Q000378:metabolism; D002417:Cattle; D002460:Cell Line; D017931:DNA Primers / Q000235:genetics; D004198:Disease Susceptibility / Q000473:pathology*; D006566:Herpesviridae Infections / Q000378:metabolism / Q000662:veterinary*; D007150:Immunohistochemistry / Q000662:veterinary; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D009831:Olfactory Mucosa / Q000821:virology; D012333:RNA, Messenger / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D012376:Rodent Diseases / Q000378:metabolism* / Q000821:virology*; D018709:Statistics, Nonparametric; D018140:Varicellovirus / Q000472:pathogenicity*
chemical_list: D000956:Antigens, Viral; D017931:DNA Primers; D012333:RNA, Messenger
keywords: Athymic nude mice; Brain; Equine herpesvirus 9; Immunodeficiency; Immunohistochemistry; Nasal cavity; Olfactory bulb; Virus infection